


Mission Last day Sunday

by GreenFalls



Category: Gravity Falls
Genre: F/M, Fluff and Angst, Sibling Incest
Language: English
Status: Completed
Published: 2020-04-11
Updated: 2020-04-11
Packaged: 2021-03-02 01:08:31
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 5,281
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23596618
Author URL: https://archiveofourown.org/users/GreenFalls/pseuds/GreenFalls
Summary: Dipper and Mabel had move together. After a smooth few months feelings start to emerge.
Relationships: Dipper Pines/Mabel Pines
Comments: 6
Kudos: 10





	1. Before

**Author's Note:**

> Check out Princest Beck (@BeckPrincest): https://twitter.com/BeckPrincest?s=09
> 
> This fic is based in her comic.

“We move in, finally” dipper said with the phone on hand and his thumb pressing recording. ”I mean we get here a few months ago but you know, the last box open, Mabel stop remodeling her room, for now, and I have use all of my cloths so the pile is big and smelly, for sure Mabel is in a few days to kick me out.” He sight. ”Sweet home”.

He ended the message, then stop and watch, one mark, they are disconnected as expect. Traveling to one corner of the world to the other don’t make it easy to keep in contact. He was tired, for much of the fake optimism he tried to show, it wasn’t easy. This promise of keeping them up to date. He wanted to properly tell them how much is going on, the many story that have been accumulated in this small apartment just in a few months, tell them that they are fine, great even. The first time living alone and they handle everything. That with Mabel by his side they can deal with anything.

It can’t be that he miss her already. A week with her friends and here he is, alone and sad. Is this his first week without her? He could call his friends, a few he got in college. But it´s not much a people craving that he feels. Talking to his grunkles might made the trick but no luck on that.

“Well, at least do laundry” he said to an empty apartment. He was truly desperate, laundry of all things, but there he was, working his way through the pile. _I can´t wait to see her face, Mabel been pushing hard for me to clean_ , he thought with a smile on his face. 

And in the laundry room. He started with organizing his pile to different piles. He knew it would take multiple wash circles. So to work. He numb himself in the labor when he make contact with a towel. Is that towel? He trough it to one pile. And back to laundry. Everything was fine, he repeated in his head, nothing weird going on.

Who is he trying to trick? He knew something was different. As much he wish he could brush it up, it happen. When was the last time he had seen his sister so close to naked? When they were six? seven? The contrast was too much for him. They have living together for a few months and they manage to keep themselves from exposing each other. Super easy, not the first they share a house even if they were other people living with them, not major incident. Not even sleeping on the same room cause this much. But this time it did.

Dipper had been coming back to that event multiple times. Hunting him to the bed. 

“Dipper!?” he listen the yell. Mabel, he figured, from the bathroom.

“Mabel what you need? Paper?” It wasn’t the first time, Mabel seem to develop the habit to use him as service. Her memory is not that bad, right? Doesn’t matter, he already moving, it wasn’t a big deal, helping her is so natural for him, without much thought on his head or hesitation he move. He was already on the closet.

“A towel!” and a towel it is. He grab the one on top and goes to her.

“Here” he said in front of the bathroom.

“Thank you. Now give it to me” Mabel said while extending her arm.

Dipper was up to leave, his task was done successfully, and his sister was please. So he step back when he remember something.

“Mabel, do you know which are yours free days? A weekend would be great but I can-”he was interrupted by Mabel scream. He got caught off guard, a few second past before he goes to protective mode. ”Mabel!” he said while knocking “everything ok?” He starting to get worry, then he hears giggles. ”Mabel?”

“I am sorry” she apologize between chuckles. ”it’s just what I am supposed to do with this towel, it´s tiny”.

“Oh, dammit, sorry let me bring you another” he said now at easy, feeling dumb. He gives his back to the bathroom when the door open.

“It’s ok, the towel is small but it did the job”

“Good, well just be sure to get a da-” and he saw her. That towel wasn’t just small, it was microscopic. It barely cover her body. Everywhere he looked was all legs, and cleavage.

“Better we talk later” the words feels that come from far away. Dipper tried not to stare at them, he can’t keep this up. He finally nod. ”Then g’night dip” and there’s she went, he was still kinda out of it but even then he swear she giggles her way to her room.

Something is wrong. Mabel is not acting like herself. The way she move, the way she talk, the way she laugh. The way she touch him. Somehow they had change. It wasn’t like that, it didn’t feels like that. The other day she was wearing too little cloth. Like, he knows she is on the house, been comfy, resting but it really doesn’t help.

He just making excuses, he is the problem. No more than a weirdo, he had become. And what moment she transform on his eyes? Too subtle, too slow to perceive really. If this is how things are he needs to act fast, this can get worst. And for any circumstance he should bring this up. This die in him or with him.

The new determination calm him. But why? If He could ask for a terrible ugly sister, for someone else, could he? What a down side of having Mabel as his twin. And after all she have done this is what he gives back. No fair. He should be better. For her.

But how? He still can´t let go, the image forever preserve in his mind. Mabel and that stupid towel, another one, let’s be honest, another one. She is so defend less with him. And why wouldn´t she for all she knows he still her caring brother. No a horny creep. How long he could justified keep it a secret. Having this crap inside of him. Thinking this and that about her, about her body, from head to toe. The fact he sometimes can’t sleep, too worry, in a loop. And how he just can’t touch himself anymore with his mind been hunted by her. He is such a fuck up.

He wouldn’t, right? He is not a danger to Mabel. Isn’t he? He can´t. He need to stop thinking, nothing good will come out of it. He take a breath, deep and slow. This is just a face, probably will go away like it came, and back to normal.

He let the topic a side, grab his poor hopes and keep moving, he have a life after all, plus Mabel.

A text pop up. His DD & More D group chat. He look at it, not much, the usual conversation for which days they can reunite. One of the problems of a mismatch group of college students is their so inconsistent free time. They have been together for a while so they even pick classes to align with each other. So with college well place it was everything else that stop them. Now, he is not one for much activities. Dipper socials interaction were limited. So not much problem from his part. He can go at least ones a week, no problem.

He goes first on his mind. College take three days were he puts everything on. Heavy continuations of classes he already is used to. Monday, Tuesday and Thursday. The last can work. He have the night for it so it’s possible. Let’s see, was he busy? He have movie night that Wednesday. Mabel wants to drag him to see the new Pixar movie. She was so excited. So no Wednesday. The weekend is a maybe but he needed to check on Mabel first if she had something else planed.

He pocket his phone and search for her. She change herself on pajamas and on the couch with everything at reach, from snacks, the remote, her phone and on top it all, a blanket. Strongly comfy, how it was no end. 

“Wow, already on cozy mode” he said acting surprised on her overwhelming rest. ”It’s kinda early for that”

“I am saving energy, this is just mere preparations for the trip” she said letting herself go deep on the couch.

“Trip?” He ask, that did surprised him.

“You forgot, the one me and the girls will go” she said with a little excitement break her perfect state.

“Right. So it was this week, yeah I forgot” he was shocked by his disappointment. Did he really care about it that bad? ”Well I happy to hear that”

“And?” She said incline to his direction. What was she expecting? She seems to read his mind. “Why are you here? You need something, I hope you have a good reason for interrupting, I Cleary busy. So spitted out!”

“Nah. Just checking on you”

They said their good byes, Mabel was left on her energy saving state, and dipper go back to his room. Pop out the phone, all week it is. With that settle, he sigh, tired. He already miss her.

* * *

Almost the end. It was just a week. A week. He can survive a week. It wasn’t that big of a deal. He may not remember the last time he was alone in a house but that doesn´t matter. For what he care she can be out for a month. She needs this, she had been doing so good with college, so much work needs some or as much rest. So it’s great. He was going to be a good brother and sulk on silence.

And back to his phone. Dammit! He really don´t have anything. His stupid responsible ass had done every homework. It doesn´t make sense, the free time. Play, watch, read. A great amount of opportunities are open. But god! He doesn’t feels like doing anything. He can´t believe it but he actually miss his sister this much. A week and here he is looking at his phone for any chance that she may have read his message. But yet again he see an unread. She haven’t connected since lunch. Well, nothing he can do about it.

Defeated he put it aside. Watch a show, any show he needs the distraction. He throw himself to rest town. Snack and blanket, same as her he let the couch eat him. Hours of white noise later he was found sleep.

“Hey!” He jump awake. ”What is this? Stealing from me?!” Mabel, in all her glory. ”Rest town from the snack, TV, the blanket and even the same spot! Thief!”

“That’s a serious accusation. I am not a thief. Rest town is public domain” he said, big smile. He was surprise. Did he sleep for a whole day? That doesn´t matter now. Without losing a bit dipper continue “Show me a patent”

“Unbelievable, my own blood, how could you?” She said with exaggerated expression of betrayal. “If justice is not by my side then…”

He knew were this was going. And before it hit him he block the pillow. A goofy pillow fight started. Horrible over acting, an increasing convoluted plot, a lot of giggles. When it ended both were tired taking a break on the sofa, a re-watched episode on the TV, cuddling together.

“So?” Dipper finally ask.

“Yeaah?”

“What happened? Why didn’t you come tomorrow”

“Ah, yes, that” she stop to take a deep breath. “Not much, Melanie the party pooper”

“Who?” He swear he never had hear of any Melanie.

“An invited bitch, really noisy, shut down Sunday” she said, anger and resentment filled her voice, but something more, he notice a faint of a smile.

“So Melanie arrived faster than we think, eh? She for sure throw water on everything on the plan for tomorrow.” He said smiling, a quick eye contact confirm it.

“The storm take a turn right to our butt. And I was having such a good time!”

Guilt started to bubble up, the happiness of seeing her taste awful is his mouth now.

“That’s terrible, I’m sorry that happen, I know how much this trip mean to you”

“Yeah, but what can you do, nature herself ruin it” she said defeated. It’s true the last day was lost, unless?

“How about we go out tomorrow?”

* * *

Tomorrow came and they decided to go to the pool. It was a slow day. So they expected to have some space. Mabel recover her energy, now with a place, she was on a mission, the revival of Sunday. Dipper go along, he was in a mission too, Mabel is going to have a great time, he will be sure of it. And with that the urges for water from the vacation push the pool as the most appealing idea.

Without doubt dipper offer for the ride, and the payment. _You deserve a great end for your vacation Mabel_ , he had said when ask, for how much you work all this time, this is not much. And we that he lead her.

Dipper’s internal battle continue. He won’t let this creepiness to affect her. He can overcome it, he will overcome it. Nothing can stop him for been the best brother for Mabel.

Now on the wheels, stiff as he can be, taking as serious he could the situation with Mabel at his side, narrating the way there like a mission impossible movie with all and soundtrack. God! He was determined, scared and laughing. What a mess. But he couldn’t take it that seriously, even with everything, they were fine. Nothing really change. He can do it. Having her now, so close, give him strength. If he needs something to probe he is good for her, nothing better than her laughter.

Well that didn’t last. As fast she change, that as how far he got. And there she appeared, a new swing suit. He is weak. A two pieces. That’s new. That was not on the plan. He is not prepared.

“How it is?” she ask. Beautiful, incredible, a crime, torture. Too good to be look at.

“It’s… nice” he gulp on that one, listening to himself, not good. ”It’s new? I never see that one”

“Yeah. I buy it when I was shopping on the trip. It’s not bad, isn’t” she ask with genuine worry. Wasn’t a mirror on the bathroom? She look gorgeous.

“Yes, really good. I was just surprised to see you on …”

“Two pieces, yeah I know, not my style, but I was push to buy it. Plus they make me promise I will use it today. Maybe we had to come back early but, you know. Mission revival of Sunday. This” she show herself with her hands. _Damming don’t look it directly_. ”Is part of the package”

He nods on agreement. Those girls really put him in a dangerous situation. But nothing like looking the other way can’t fix. Plain and simple, little touching, focus on her eyes, and before he knows it they will be back home. The operation fun, Mabel last day, Sunday start. He stood with restored confidence, and hope.

“Hey! Brobro are you going to stay there” she said bringing him back to reality. He then look. _Oh no, no, no, no, no, noooooh_. On her hand, is that? ”Come and help me put the sunscreen”

_Don’t act weird you danm creep, just go there and do the job, she will start asking why you can’t, so go._

“Sure Mabes” he said poker face on.

And there he was, full on contact, first rule and broken. He put a good amount of cream on her hand. Even with all going on he needs to avoid Mabel´s skin to burn. All his live his protective side emerge to save him. Focus on that.

“Nice. Get it everywhere” _not helping Mabel_.

“Done!” he could jump of happiness, he did it! A normal sibling interaction. Nothing weird going here folks. Just twin having good time.

“Thanks dip”

“No problem”

“Now your turn! Give me that back!” 

_Oh god ._

**Notes for the Chapter:**

> Link to the comic:
> 
> Page 1: https://twitter.com/BeckPrincest/status/1233601872876826624?s=09
> 
> Page 2:  
> https://twitter.com/BeckPrincest/status/1235764857829457925?s=09


	2. After

**Summary for the Chapter:**

> We are now with Mabel POV. The aftermath of the Last Sunday Pool Mission.

“Are you sure you are ok?” they move back to their spot. Mabel still feel the embarrassment. Jumping like that, stupid two pieces, stupid friends. She knows she ask for help for a new swing suit but come on at least something that can keep up with her. Her old one piece never give her so much problem. She starting to calm down, the laugh never stop, no one reacted to the number she pull up. “Mabel?”

“Oh! Yeah, I fine. Everything seems fine” she said with her best enthusiasm, but he should have notice the fear on her, his face still worry.

“Need something? I have your favorites on the bag, smile dip!” he said taking it out for her.

“Uuuuh, great! Really?!” she was actually surprise. He did get it. She get close to take it but look up, again something go through her. She didn’t like it, at all. Whatever it is doesn’t feels family friendly. She focus on the price, open and then mouth. The sugar hit fast.

“Better?” he ask and she nods. She feels better now, and it seems to show, another look at his face, a pleasant smile, how happy he got just for her. Nope he is not worry no more. He stare away, and she release the breath that she didn’t know she was holding. Conflicting feelings were form, a part glad he break the eye contact, the other disappointed. Not good. Not good.

“Wait here. I will go for the top” he said and go back to the pool. She looks at how he goes back to the corner they were. He goes super sneaky, slow and acting like he goes back for a swim. Not look! Nothing is going on! Yells that clumsy movement. The miracle happen, no one was paying attention, good thing for her and dipper dignity. She giggles, it’s just so dumb, embarrassing, stupid, and she loves him so much. Too much even.

* * *

End back at home. They stay on the pool eat and talk. It was nice after her dumb but makes herself enter a disaster. God she was scared. It could had been so bad. But dip was there. His big dork-self save her but. She sight, not sure why, reason pop on her head but she didn´t dig farther, nope, she wasn´t going there. She already have enough. Why she was so greedy? He have him, she always had. And now she couldn´t stop wanting more.

How can she bring up that she was glad that storm came. That not even a week jet she miss him bad! Why she put on that bikini? Not her style for sure. Like it was so plain, a bikini from a tourist store, clearly over price, a simple stamp of colors with lunar. It´s cute not gonna lie, and it did show off her puppies. Which not really matter if it wasn´t a boy there to impress. Well, no any who might be interest.

Dammit, dammit, dammit! No, no! not touch that. Not dare go there! So much on not be greedy. Mission not be a creep not looking good. When was the last time she feels like this over someone, so nervous, so scared of his reaction. What to say? She never had so much to lose.

Her common sense still up and ready to pull of her bs. She can´t, but the way he cares, is possible, maybe. He loves her, for sure, always, but now isn´t enough. How much she wants to touch and be touch, embrace him all. What hope she have? The few looks he gave to her chest? How he move his hand with almost adoration? It´s even worth it, this is a big bet. And she is happy anyway. They are now together, living on their own. The twins versus the world. Who needs kisses, or sweet words of love?

This wasn´t going anywhere. She needs to get out of her head and put this problem on a real solution. She needs the big guns, a new mission, she needs to see the world, alone, space from dipper, and she is getting ready for an old and great boy hunt.

It´s time, the favorite past time of America. Now in her hand the list, her phone, of every half decent boy on this damn place. Nothing but the best. Face it creepy feelings ones she gives a serious look at this and is over. Simple enough Mabel go through the contacts. Information of a series of people appear, a basic template with names, number, mayor, a summary of her opinion and relationships. Her list of contacts were extensive, she had accumulated a lot of people with the passing of the year. But for now she needed the boyfriend material. Easy enough, Mabel is no newbie, she is prepared, just a mark in each name related to school, work, family, and of course boys. A heart.

And there she was prideful. This have to work, it needs to be. What else is beside? The list refresh and hunt began!

She start scrolling, names and faces past one after the other. Aghh, that idiot still here. Nope, delete. She had talk to this one, real nice, and gay. Remark as a friend and moving. A lot of this is out dated. She really let herself go, so long since last time and all a mess. She saw so many no one catch her eye. _Como on Mabel, you needs this. This is an emergency, if not for you for dipper._ That do the trick, she picked.

Ok, looking good, yeah, she knows that one, he is nice, tall, with that she goes and find him on social media. Seems like a great guy nothing wrong on here. Oh! Yeah too good to be single. She stop on a recent photo, someone was enjoying the break, he and pretty blond on the beach. She waits, year on this make her prepare for this kind of situations. The hit of disappointment will soon came but this can´t affect her, she needs to continue! And nothing. That was new. Months since the last boy hunt and she can even bring herself to bother.

¨Mabel!?¨ dipper yelling her name. she jumps surprise. ¨Come here, I need you¨

And she goes. The itch still affecting her. She goes scared, excited, scared of her excitement. And more but she goes he needs her after all.

* * *

¨When? Dipper! This was not part of the mission!¨ She said with undeniable excitement. A bunch of snacks, soda, a marathon ready to play, and her spot with her blanket. He did that for her. God! That dork, how could he? This make her so happy that it hurts.

¨I know, I know. But how can you end final Sunday without something special? Easy question. You can´t¨ he remove the blanket on the couch and tap it. She got the message and sit down. Feels nice, this can´t get better. Dipper like wanted to show her wrong he takes the place at her side. 

And there she is, on the stratosphere, to the moon, to the stars. Someone calls NASA she is out space. Oh, oh, is that impossible force of a black hole? Because she getting closer to dipper. How can she avoid it? An impossible force that was, push her to touch, push her to feel. And after an awkward movement they settle, like pieces that meant to be. Mabel embracing dipper and he around her.

¨Thank you¨ she whispers, no need for more, with her head on his shoulder. ¨I love it, I love it all¨

She feels the tension leave his body. His breath becoming calm. And the corner of her eye she sees a big smile.

With that they let the TV take them away. And of course they ruined it with constant commentary, that was reduce to both trying their best to make the other laugh. Not difficult task, they were high with each other. The more exaggerated movement more commons with the marathon were absent. The jumping, the trips to the bathroom or kitchen, the dancing (mostly hers). How could they when neither wanting to break the touch?

She was so close to him. She could feel everything. Every move, every breath. And an easy access to him. She tries to be subtle, but she doubt how good she sneak every touch, feel, push. It was a feast, an all eat, and she was so hungry.

For the most part they stay together while pretending it was just another night for them. But later she notice. Dipper was more anxious, scared even. If she was great before at telling how he feels, now, so close to him was even easier. She saw him open his mouth, and waited. Nothing. He open it and then close it again, she pretended not to see, face up front, a light leaning on her right to see the little she allowed to herself.

Yep. He is going to say something pretty heavy. What could it be? She sits there waiting. His constant fear, now affecting her. Now both nervous. Her mind goes to the worst scenario. He can´t be, he doesn´t know a thing, she is save. Her new state didn´t help. She push more on him the origin of her fear, for comfort. But what better than him?

“Mabel?” he whispers. Oh no, oh no, no, no, no. There it comes. “How is everything?” so a vague question. Someone else is avoiding the subject.

¨Fine¨ she lied.

¨Gre-great¨ he said and then swallow. “College? Friends? “

¨Yeah, nothing to report. I am fine¨ she lied again.

¨Cool¨ come on, spill it out! Just get over it. You got me, I am disgusting. You shouldn’t let me touch you. I getting more than hug out of this pal. Dip I am so-

"And your love life¨ and he interrupt her. Where are you going dipper? He seems not sure himself really. ¨You know. Boy hunt¨

¨Yeah, that. Not well really. Right now just laid back, polishing my tools, waiting if I find someone¨ what a lying bitch. No doubt. But his reaction surprise her. A more calm breath, and small sight of, can be? Relieve. And as fast the fear was contagious as fast the relive. She let her own sight. And she found herself hopeful.

¨But now that I think about it¨ she said like she is not scared to death. ¨Maybe there is one guy¨

¨Cool¨

Dipper reaction jump her back to the moon. He seems expecting it, but still goes back to an anxious mess. He started to get uncomfortable on his spot. He nodded hiding his disappointment, and it could be, pain? HA! Wuhuuuu! YES! I mean, no. That´s awful! God! She was jumping to an extreme to the other. She was so happy, but dipper needs her. This bait had come far enough.

She stop looking a way, and went for his eyes. He was running from her sight, he couldn´t look. And she understood that perfectly. But she won’t let him do that. A tap on his shoulder, just a grunt in response. She insisted, until he give up. His eyes still running from hers. But she hold still, she was not going to let him avoid it. They needed this. To see it, to clear it, to know.

And then they look.

They were lost on a trance, possess they move. She was focus on his face, her fear push her to find disgust, hate even. At least anger or pity. But no matter how much, or how long, she only sees a starving desire, and love. So she move, getting eager for more. In what it feels forever they get closer and closer until a kiss. A little pick, texting the waters of his soft lips.

She taste the snacks, sugar, salt, a cocktail of flavors with each movement, and now closer, pressing chest with chest. She couldn´t get enough of his body, the heat, the form mold by her. The agitated breath making his chest go push and back. The hot air from his nose. She loves it all. 

The intensity was overwhelming, she never feel like this and she couldn´t think in anything else that can surpass it. Not an impressive claim, her brain become a mashed potatoes. They keep going, zero intention of breaking the kiss. But the lack of air started to get them dizzy. More and more pass. The never ending placer go to an end.

Both were taking big and desperate breath now back to the surface. Not long they took a look of each other. They found a sweaty mess, and big satisfaction all over their faces. She couldn´t stop it, the laugh comes out. Started as a giggle to a bigger one. Dipper burst too while she rest on his chest, head on his shoulder, taking a sit on his thighs. Mabel was over Dipper and he was around her.

She was filled. From what? Her curios mind wonder. It wasn’t like her crushes and boyfriends. She take a deep breath. She couldn´t get enough, he smell so good. She feels his arms all over her. And her sniff seem to give him a green light sniffing her hair. She giggles one more time on his chest and he back on her head.

No, the feeling is not new. It was the good old love she remember. Bigger and a with a new light, but no a bizarre thing that pop from nowhere. They love each other, like always, since even before they were born.

They rest calm. A lot to face on the way, but they are fine, everything is ok. They have each other.

* * *

¨hi! Grunkle Stan, grunkle Ford, it´s me Mabel¨ she said with excitement. It was another week pass so how they promise they were going to send a message to update their grunkles.

¨Mabel, I haven´t press record yet¨ dipper said with smile and loving eyes. As much he is amuse by her, they needed to do this. Mabel start grumping, he was just out of it.

¨Well do it then, you wasted a perfect hi!¨ she was overselling her anger, forcing a pathetic imitation of a frowning brow with lips struggling to not smile. ¨You know what give me that!¨

¨Nope, not gonna happen¨

And there were the twin ¨fighting¨ over the phone. Both adults acting like kids, in a mess of giggles, of graving, pushing, biting (mostly Mabel).

¨Enough. Mabel we need to do this.¨ dipper said calling to ceases the fire.

¨Fine! But not make me waste another hi¨

¨Sure, for now I will be hiFriendly to reduce my hi print¨

Mabel pretended to not be impress. But the lips lost the fight, a big smile form. She stop been delight by Dipper to look at the phone.

¨Wait did you send that?!¨

Dipper was puzzled for second until he fallow her gaze.

¨Oh, Shit¨

Message record it. Message send. Message received.

**Notes for the Chapter:**

> Thank you for reading. I knew at this so any words you want to share with me i welcome it.


End file.
